Velodyne HGS-12 review in HFN

[severnsource]

Very interesting review of the HGS12 in the May Hi-Fi News, by Martin Colloms. The review is positive and he comments on the cleanness of the sound.

The most interesting part however are the measurements that he published, not something you usually see in woofer reviews. Two points that I noticed were that the spl at 20hz was only 94db at 1.5% distortion, presumably this was the maximum level before limiting and must have been measured in room. The other observation is the very poor consistency of the crossover, that is that the slope varies significantly with changes in crossover frequency.

The maximum SPL is probably reasonable for such a small box, but the crossover inconsistency seems something of a drop off in a piece of equipment that retails for over £2000, particularly considering how easy crossover design is.

I don't suppose any of the commercial competition are any better, but it doesn't look very good value to me.

[Apocalypse]

IMO it would be lunacy to buy either the HGS 10 or 12 when for a few more quid you could get the HGS 15, and if I hear any more crap about WAF I'll explode. If you can't get the sub you want then don't get something you don't want.

Flamesuit adorned and ready for testing

[Tom Vodhanel]

>>>Two points that I noticed were that the spl at 20hz was only 94db at 1.5% distortion, presumably this was the maximum level before limiting and must have been measured in room.<<<

That sounds about right. When the HGS15 was measured in room it maxxed out around 95dBs/20hz 2 meters from a corner loaded unit.(Tom Nousaine's data)


>>>The other observation is the very poor consistency of the crossover, that is that the slope varies significantly with changes in crossover frequency<<<

Sometimes that is designed into the crossover on purpose. I have no idea what the context of the review was so I'm not sure if the reviewer is aware of that or not?


Tom V.
SVS

[Ian J]

Originally posted by Apocalypse
if I hear any more crap about WAF I'll explode.

I must admit that I agree and feel that it's a shame that so many people have to buy second rate equipment as they appear to have no say in what they are allowed to have in their wife's house.

I read somewhere that Home Cinema is supposed to be a male preserve but reading many of the threads started in this forum you would think that it's the chosen hobby of mice.

Any spare room in that suit of yours Phil

Originally posted by Apocalypse
IMO it would be lunacy to buy either the HGS 10 or 12 when for a few more quid you could get the HGS 15, and if I hear any more crap about WAF I'll explode. If you can't get the sub you want then don't get something you don't want.

Flamesuit adorned and ready for testing

WAF? please elucidate ...

[Ian J]

Originally posted by Jonathan West
WAF? please elucidate ...

Wife Acceptance factor otherwise known as a compromise.

Originally posted by Ian J
Wife Acceptance factor otherwise known as a compromise.

At this stage I have yet to find any Wife that I find Acceptable

I thought the Hi Fi News review was very positive, the final conclusion write up mentioned something about it offering the deepest, cleanest (measurably so, rather than subjective) bass around... and surely that's what everyone's after?

Are we talking subs or WAF here guys?
WRT to measured sub output, a thousand and one things can affect the results that a reviewer gets. The best data is always that which comes from a very large sample range, with a wide range of tested equipment. TN's figures are great because he has tested practically everything available, but they only serve as a good indication of where subwoofers sit in the heirachy of low end performance.

Yeah reason maybe why I'll be buying the Q150. Size matters...with subs it's the lack of it.

[Nobber22]

Originally posted by juboy
the final conclusion write up mentioned something about it offering the deepest, cleanest (measurably so, rather than subjective) bass around... and surely that's what everyone's after?

Second that whole-heartedly Juboy!!!! IMO the only people who (should) really care about ultimate sub output measurements are those like Tom V who make them (no offence Tom).

The rest of us just want to listen to the bleedin' things pounding away in the living room!

[severnsource]

Originally posted by Nobber22
Second that whole-heartedly Juboy!!!! IMO the only people who (should) really care about ultimate sub output measurements are those like Tom V who make them (no offence Tom).

The rest of us just want to listen to the bleedin' things pounding away in the living room!

Well thats one point of view. Personally I can't afford to throw £2000 away on a piece of equipment with the sole function of reproducing a very small and not very important part of the spectrum and then find that it doesn't work as claimed. These things don't seem to be available for home demo so you would be taking quite a risk buying one blind. Measurements made by a reliably competent person give you a baseline for comparison without having to take into account the prejudices of subjective reviewers.

As far as I am concerned the review has told me that this sub does not have adequate output at very low frequencies, something that I would not have known without the measurements.

Bill

Originally posted by severnsource
Well thats one point of view. Personally I can't afford to throw £2000 away on a piece of equipment with the sole function of reproducing a very small and not very important part of the spectrum and then find that it doesn't work as claimed.

Hi Bill,
I'd like to address your post if I may.
Firstly, in most cases, a subwoofer represents the LARGEST part of the sonic spectrum. Most systems are run crossed over at approx 80Hz, therefore, the subwoofer outputs ALL channels <80Hz sonics plus LFE. In my humble opinion, a subwoofer is the single most important element in most of todays home cinema sound systems.

This is not meant to be a defensive post by any means but I would like to point out that whatever Velodyne claims, I have always found to be true. For example, they do not claim figures of 15Hz to boost the sales of their baby VX-10 but instead a very pessimistic (anechoic) figure of 36Hz. Of course, none of us use an outdoor playing field as a living room so once "room loading" is taken into account, this figure is drastically improved. However, room loading is variable and is dependent on many factors the biggest of which is the room, size and location.
Which is why Velodyne do not publish ridiculous "in room" (what room?) figures.

Originally posted by severnsource
As far as I am concerned the review has told me that this sub does not have adequate output at very low frequencies, something that I would not have known without the measurements.

Whatever you think this reviewer might have told you, the little Velodyne HGS-12 goes down to a very healthy 20Hz -/+3 dB's
Anyone who knows anything about subwoofers will tell you this is not easy to achieve by any means and the percentage of subs on the market that can output to this true figure at the low distortion measurements the HGS-12 can do it in is few and far between.

[Matt F]

A few points. A review of the HGS12 was also done by Audio Magazine: http://www.velodyne.com/pages/reviewsp/amhgs12_1.html

They measured 99dB @16Hz (damn impressive depths from such a small box), rising to 144dB @60Hz. The reason it's lower at the lower frequencies is because distortion is more likely down here (more cone movement) and therefore the servo mechanism steps in sooner.

I must say it is refreshing though to see a mag publishing distortion figures and whilst 94dB might not look that impressive, I'd love to see just how high the distortion would be on similar sized non-servo controlled subs that play higher than 94dB.

As for the HGS15 comments, Tom always seems to be looking for opportunities to knock it by quoting the output figures that some reputable guy measured.

However, for balance, let's just consider the following:

1. Any 15" sub with a 1250 watts RMS amp in a decent sized enclosure is never going to have a problem with output levels.
2. The HGS15 waltzed through THX Ultra 2 certification which requires something like 105dB at 4% or less distortion.

You know this beastie is only one small step down from the mighty HGS18 and of that, John E Johnson jnr (Sectrets of Home Theatre and High Fidelity) said "The HGS-18 can go pretty much anywhere it will fit. I used it several feet out from the wall for the measurements. In that position, I could get 108 dB at 25 Hz maximum. Keep in mind, that is with very, very low distortion. You can put it in a corner and get over 120 dB at 31.5 Hz (I got 123 dB). That measurement alone will make it the most powerful subwoofer on the planet."

Okay, so the HGS15 will be a little down on this but I can assure you that it's output is still immense.

Matt.

[Tom Vodhanel]

>>>They measured 99dB @16Hz (damn impressive depths from such a small box), rising to 144dB @60Hz.<<<

The text is quoted as saying the unit maxxed out at 20hz/96dB/ <3% thd. No mention of a 16hz maximum output number is given AFAIK...although they do include the 16hz performance on the 3-D graph. I'm not sure where you got "144dBs" from(maybe a typo?)..but it was more like 114 with Keele's idea of "room gain" factored into the measurements.

>>>The reason it's lower at the lower frequencies is because distortion is more likely down here (more cone movement) and therefore the servo mechanism steps in sooner.<<<

Right, all things being equal...the cone has to move 4x farther each time the frequency drops an octave to maintain the same output levels. In other words, if the cone needs to move a total of say 8mm (4mm each way) at 80hz to produce 100dBs...that would be 16mm at 40hz and 32mm at 20hz.


>>>I must say it is refreshing though to see a mag publishing distortion figures and whilst 94dB might not look that impressive, I'd love to see just how high the distortion would be on similar sized non-servo controlled subs that play higher than 94dB.<<<

Again, agreed. I think THD figures can be very useful when interpretted correctly. Not sure where this "94dB" figure is from though...the HGS12 actually did 96dB/20hz which is even more impressive for its size.

Two other like sized units measured in the same way...

Sunfire MarkII, just over half the size of the HGS12, and $1299 vs. $2099(?) for the HGS12.

At 20hz, it hit 99dBs but had 13% THD. At 96dBs it looks to have about 11% THD ....but it is tough to tell reading the 3-D graph.

Not really too bad consider the price and size advantages for the sunfire.

-------

The MK-MX700, about the same overall size, and $1399.

At 20hz, it had no useable output and was measured with >20% thd.
----------------

The servo15 was also measured by Don Keele,

20hz, it hit 98dBs with 9.7% thd(it looks to be about 4-5% on the 3-D graph at 20hz/96dBs...but it is tough to read for sure). but from 25hz and up it pulled away a bit...with advantages of 5-6dB at both 25hz and 31hz for example. (i think the THD was in the 5% range on these).



>>>As for the HGS15 comments, Tom always seems to be looking for opportunities to knock it by quoting the output figures that some reputable guy measured.<<<


Yeah, that's me...introducing documented data---even when the data(properly interpretted) is clearly complimentary--- into the discussion just to try to *knock* something...?

Just for the record, Howard Ferstler also measured the HGS12 at 20hz and measured it maxxing out at 100dBs. The Paradigm servo15 hit 110dBs/20hz for him...which was the same as the F1800mkii 18" servo from Velodyne. I think the ct150 hit 97dBs/20hz but I'd have to double check on that. HF doesn't include any THD data though, just pushing each unit until *audible* distortion is heard.


Tom V.
SVS

[micb3rd]

Originally posted by Matt F
A few points. A review of the HGS12 was also done by Audio Magazine: http://www.velodyne.com/pages/reviewsp/amhgs12_1.html

They measured 99dB @16Hz (damn impressive depths from such a small box), rising to 144dB @60Hz. The reason it's lower at the lower frequencies is because distortion is more likely down here (more cone movement) and therefore the servo mechanism steps in sooner.
Matt.

144 DB @ 60 hz, I think you mean 114 DB @ 60hz.

144 db in home would be insanely loud and pritty hard to achive.

Tom V nice too here from you, I have been a member of HTF for quite a long time, I have followed the SV Subwoofers from quite early on.

Just a small query what kind of output at 20 hz does the SVS Model B4-Plus give in a medum sized room, I surpose finding enough power to run one of these monsters flat out is quite hard.